1. Field of the Invention
The invention relates to a printing system in which a printer or an image forming apparatus is used as an output side. More particularly, the invention relates to a print control apparatus having a function such that information regarding a recording medium serving as a target of printing is obtained before the conveyance of a sheet and when a trouble occurs in creation of print data based on the obtained information,. print control, or print setting, the user is notified of its contents, a printing system, a print control method, a computer-readable program, and a recording medium in which such a program has been stored.
2. Related Background Art
Hitherto, generally, a printing system for forming a color image and obtaining printed matter at an office or in personal use has been constructed by: a printer which can output the color image; a host computer for controlling the printer and forming print data; and a communication interface for connecting both of them. Among color printers, an ink jet printer directly injects ink from a recording head onto a recording medium and has advantages such that its running costs are low, it is also suitable for color recording, the recording operation is quiet, and the like, so that such a printer is drawing attention and used in a wide market ranging from business to home use.
A large variety of sheets are selectively used in the ink jet printer in accordance with its application. There are: plain paper which is used in a copying apparatus or the like; coating paper whose surface has been coated with silica or the like in order to improve coloring by suppressing a blur of ink; glossy paper which is used to form a photograph-toned image such as a silver salt photograph; an OHP film for a transparent original; transfer paper to be iron-printed onto a T-shirt; a back print film; and the like. Further, there is a postcard for a New Year card as a type of coating paper which can be printed only by the ink jet printer. As mentioned above, a really large variety of sheets exist.
When those sheets are printed, the user previously selects or inputs a type and a size of a recording medium (sheet) serving as a print target as print settings on a printer driver and executes the proper printing onto the sheet on the basis of the settings.
A flow of processes of such a general ink jet printer will be described hereinbelow with reference to FIG. 37.
In step 3701, the user instructs a PC to make a print request. Generally, the print request is instructed by using a mouse or a keyboard. It can be instructed via an audio input device such as a microphone or the like.
In step 3702, the printer driver for managing the print settings or the like is activated. Actually, it is activated when a display screen is shifted from a print setting display screen displayed in response to the instruction of the print request to a display screen for performing a detail setting operation.
In step 3703, print set contents which have previously been set in the printer driver are displayed by using a display apparatus such as a monitor or the like.
In step 3704, when the user wants to obtain a status of the printer, he instructs to make a status request. It is not always necessary to make the status request.
In step 3705, when the status obtaining request is actually instructed in step 3704, the status request is made to the printer.
In step 3706, when the status request is made in step 3705, various status information showing the presence or absence of sheets, a residual amount of ink, a state of the communication interface between the PC and the printer, and the like is returned to the PC.
In step 3707, when the user requests obtainment of the status information, its contents are displayed onto the monitor or the like.
In step 3708, the status information which is displayed in step 3707 and the preset print settings which are displayed in step 3703 are confirmed and, if they are changed, a change instruction is given.
In step 3709, when there is the change instruction in step 3708, update information of the print setting to which changed contents have been reflected is displayed onto the monitor or the like. The user can repeat the processes in steps 3708 and 3709 and execute desired setting if he wants to.
In step 3710, the user instructs to start the printing. Thus, the actual printing operation is started. If the printing is directly started without displaying the detail setting display screen of the printing from an application which is being operated on the PC, the process is started from this step.
In step 3711, the printer driver on the PC receives the print start instruction and forms print data corresponding to the print setting. Specifically speaking, various image processes such as color conversion, binarization, and the like, command creation for printer control, and the like are executed.
In step 3712, the print start request is made to the printer by the PC.
In step 3713, in response to the print start request, paper feed is started to convey the sheet set in a tray or a cassette of the printer to a print position. If no sheet is set, its information is grasped and notified to the PC when it inquires the status.
In step 3714, the paper feeding operation is executed. In this instance, the sheet is conveyed to a print start position.
In step 3715, the status request depending on the intention of the user in step 3704 is certainly made here, thereby obtaining various status information such as presence or absence of the sheets, and the like.
In step 3716, the status information is returned to the PC.
In step 3717, when the status information obtained in step 3716 indicates the occurrence of a fault such as absence of the sheets, power-off, or the like which becomes a problem upon printing, the user is warned of the generation of an error. The warning can be made by a display onto a monitor or the like or an audio output using a sound source.
In step 3718, the print data formed in step 3711 is transmitted to the printer. Although the transmission is performed at one certain point and completed by the transfer of once in the diagram, actually, the print data is divided and transmitted in accordance with a memory capacity or data processing ability on the printer side or transmitted during its creation.
In step 3719, the printer transmits the received print data to the printer engine and prints.
The above processes are the flow of schematic processes of the general ink jet printer.
When selection from a number of types of sheets mentioned above is left to a judgment of the user, if he feels no necessity to select the sheet type, the print data is printed in a print mode set by a default. A case of printing without calling the detail setting display screen of the printing from the application corresponds to such default printing. There is also a case where the printing suitable for the type of sheet cannot be performed because the user feels it tiring to select the proper type of sheet from many selection items every printing, an input different from his selection intention is made, he lacks knowledge of the sheet which becomes a target of printing, or the like. An expression “the printing suitable for the type of sheet” shows the convenience of the printer vendor, and it does not mean that the user is willing to make the selection. Regardless of the sheet type, the user desires the printing of high quality and a high speed.
If the printing which is improper to the sheet as that in a state where the sheet type has erroneously been set, that in the default setting, or the like is executed, there is a possibility of occurrence of the following problems. That is, if the printing is executed to plain paper in the setting of coating paper or glossy paper which is meant for the printing of high quality, since an ink consumption is large, the ink blurs and is wasted, and at the same time, it takes surplus time to print. If the printing is executed to a media such as glossy paper or the like which is relatively expensive in the setting of the plain paper which is not accompanied with the high print quality, since desired image quality is not obtained, the sheet is used in vain.
In consideration of those drawbacks, there is a printer equipped with a sensor called a media sensor for specifying the type of sheet.
A flow of processes of the ink jet printer with the media sensor will be described hereinbelow with reference to FIG. 38.
Since processes in steps 3801 to 3810 are similar to those in steps 3701 to 3710 in FIG. 37, respectively, their description is omitted here.
In step 3811, the printer driver on the PC receives the print start instruction and forms primary data corresponding to the print setting. Unlike the example of the general ink jet printer, in this system, the creation of the print data according to the type of sheet is performed by the printer main body instead of the PC serving as a host computer. The system is limited to the creation of the data which does not depend on the type of sheet here. Specifically speaking, since various image processes such as color conversion, binarization, and the like are executed by the printer main body, the system is limited to the positioning of a print object, creation of a command for printer control, or the like. Upon printing of image data such as a photograph or the like, multivalue data of RGB is transmitted to the printer.
In step 3812, the print start request is made by the PC to the printer.
In step 3813, in response to the print start request, the paper feed is started in order to convey the sheet set in the tray or cassette of the printer to a sensing position.
In step 3814, the paper feeding operation is executed in response to the start of the paper feed in step 3813. At this time, the sheet is conveyed to a position where it can be sensed by the media sensor.
In step 3815, the type of the conveyed sheet (media type) is sensed. It is assumed that the media sensor has been attached onto a carriage on which an ink cartridge or a print head has been mounted or halfway of a conveying path.
In step 3816, the type of sheet which is at present being conveyed is specified from an output result of the media sensor. It can be specified by an arithmetic operation based on obtained parameters or by referring to a table. A kind of principle of sensing the media type is not limited so long as an output which enables the media type to be specified is obtained. It is assumed here that an optical sensor has been provided.
In step 3817, the status request depending on the intention of the user in step 3804 is certainly made here, thereby obtaining various status information such as presence or absence of the sheets, and the like.
In step 3818, the obtained status information is returned to the PC.
In step 3819, when the status information obtained in step 3818 indicates the occurrence of the fault such as absence of the sheets, power-off, or the like which becomes a problem upon printing, the user is warned of the generation of an error. An arbitrary method of notifying the user can be used in a manner similar to the case of FIG. 37.
In step 3820, the primary data formed in step 3811 is transmitted to the printer. A method of transferring the data is similar to that in FIG. 37.
In step 3821, secondary data according to the corresponding type of sheet is formed on the basis of information which specifies the sheet in step 3816. Specifically speaking, a process for converting transmitted RGB data into YMCK data or a process for converting multivalue data into binary data is executed.
In step 3822, the printer sends the print data (secondary data) formed by the printer itself to the printer engine and executes the printing. In this instance, control of the printing according to the media type is also made by the printer main body.
The above processes are the flow of schematic processes of the ink jet printer with the media sensor.
A flow of processes of a laser beam printer with the media sensor will be described hereinbelow with reference to FIG. 39.
Since processes in steps 3901 to 3910 are similar to those in steps 3701 to 3710 in FIG. 37, respectively, their description is omitted here.
In step 3911, the printer driver on the PC receives the print start instruction and forms print data corresponding to the print setting. Generally, in a page printer of an electrophotographic type using a laser beam or the like, the print data is frequently described by a page description language such as a postscript or the like. The data is also similarly formed by using the page description language (PDL) corresponding to the printer.
In step 3912, the print start request is made to the printer by the PC.
In step 3913, in response to the print start request, the paper feed is started in order to convey the sheet set in the cassette or tray of the printer to the sensing position or the image forming position.
In step 3914, the paper feeding operation is executed in response to the start of the paper feed in step 3913. At this time, the sheet is conveyed to the position where the media type can be sensed by the media sensor or the image forming position (specifically speaking, transfer position).
In step 3915, the type of the conveyed sheet (media type) is sensed. It is assumed that the media sensor has been provided halfway of the conveying path. Unlike the case of the ink jet printer, output information of the sensor is not used to correct the print data itself but used to optimize conditions of the image forming process according to the electrophotograph, specifically speaking, a transfer voltage, fixing temperature adjustment, and the like.
In step 3916, the type of sheet which is at present being conveyed is specified from an output result of the media sensor. A specifying method, a type of sensor, and the like are not particularly limited so long as they can be realized in a manner similar to that in FIG. 38.
In step 3917, the status request depending on the intention of the user in step 3904 is certainly made here, thereby obtaining various status information such as presence or absence of the sheets, and the like.
In step 3918, the obtained status information is returned to the PC.
In step 3919, when the status information obtained in step 3918 indicates the occurrence of the fault such as absence of the sheets, power-off, or the like which becomes a problem upon printing, the user is warned of the generation of an error. An arbitrary method of notifying the user can be used in a manner similar to the case of FIG. 37 or 38.
In step 3920, the print data formed in step 3911 is transmitted to the printer. A method of transferring the data is similar to that in FIGS. 37 and 38.
In step 3921, various conditions of the electrophotographic process are changed on the basis of information which specifies the sheet type obtained in step 3916.
In step 3922, an image is formed by using the received print data in accordance with the process conditions set in step 3921.
The above processes are the flow of processes of the laser beam printer with the media sensor.
An outline of the processes in the case where the media sensor is provided for the printer of the ink jet type or the electrophotographic type will be described with reference to FIG. 40.
In step 4001, the print start is instructed. At this stage, the information of the sheet is not obtained until the print start is instructed.
In step 4002, print data and a control command are formed in accordance with the print setting conditions.
In step 4003, the printing is started after the creation of the print data. The printing can be started even if the data creation is not finished. The conveyance of the sheet as a recording medium is started simultaneously with the print start.
In step 4004, the sensing operation by the media sensor is executed in order to obtain the information which specifies the sheet type during the conveyance or in a state where the sheet is stopped in a specific position of the conveying path.
In step 4005, a result of the sensing operation is reflected to each printer in accordance with the information obtained in step 4004. If the printer is the ink jet printer, correction of the print data or the print control method is changed. If it is the laser beam printer, the various conditions of the electrophotographic process are changed.
In step 4006, image creation as an actual printing operation is executed.
The image creation according to the sheet type is executed on the basis of the information obtained by using the media sensor as mentioned above.
However, the foregoing conventional techniques have the following problems.
In the general ink jet printer without the media sensor, that is, in the ink jet printer which cannot automatically detect the sheet type, the user has to preset the type and print quality of the sheet serving as a print target as mentioned above. If nothing is specified, the printing is performed under the conditions set by defaults. In this case, it is difficult to form the image that is optimum for the sheet. There is also a case where the printing suitable for the type of sheet cannot be performed because the user feels it tiring to select the proper type of sheet from many selection items, an input different from his selection intention is made, he lacks a knowledge of the sheet which becomes a target of printing, or the like. Consequently, there is a case where an expensive media or ink is wasted or the print time is unnecessarily prolonged. Further, there is also a problem such that in the ordinary flow, until the printing is started, unless the user requires, he is not informed of the printer status for example, whether the printer is in a state to make communication or not, whether the sheets have been set or not, whether the ink still remains or not, or the like.
Although a printer which is equipped with the media sensor that can specify the type of sheet and which automatically sets the print mode suitable for the sheet has been devised to solve a part of the above problems, even in this case, there are the following problems.    1. In the printer with the media sensor, generally, since the creation of the print data suitable for the sheet, that is, a process of a heavy load such as an image process or the like is executed after the reception of the data which does not depend on the sheet type, an arithmetic operation processing apparatus of a high speed and high performance is necessary. Specifically speaking, there is a problem such that since dedicated hardware such as high-speed CPU, DSP, ASIC, or the like is indispensable, ability of the PC of a high speed and high performance as one of the component elements of the printing system is not fully exploited. Therefore, it is necessary to provide such ability for the printer main body, and the costs also increase largely.    2. To specify the sheet type on the printer side, it is necessary that an internal ROM has a reference table serving as a discrimination reference or parameter for comparison. Since the change in specific conditions is accompanied with rewriting of contents in the ROM, they cannot be easily changed. This is because there is a risk such that the rewriting of the ROM of a peripheral apparatus such as a printer or the like makes the apparatus inoperative when it fails.    3. Once the printing is started, it is executed in the mode that is most suitable for the sheet. Although it is advantageous, for example, in the case where the user wants to print a print target which does not need very high print quality and is usually printed onto the plain paper, if glossy paper is set to the printer side and the sensing result of the sheet by the media sensor indicates the glossy paper, the high-quality printing suitable for the glossy paper is arbitrarily executed. Although the print quality obtained after the print-out is sufficient, the ink is wasted and the print time is prolonged. It is unlikely that the user desires that the printing which is enough on the plain paper is executed on such relatively expensive paper. One of the reasons for those problems which can be considered is that the system does not have means or a procedure for specifying the sheet type, thereafter, notifying the user of a specified result, and confirming his intention.    4. Since the operation to specify the sheet type is executed after the printing is started, the total print time consequently increases. Although there is no problem if the sheet type can be sensed during the conveyance of the sheet, if a construction such that the conveyance is stopped halfway and the sheet type is sensed is used, a time which is required from the stop of the conveyance to the end of the sensing operation becomes a problem. In the case of printing a plurality of pages, if a certain time is necessary to sense one sheet, it is not practical to specify the sheet each time it is printed in consideration of the print time. In the case of printing a plurality of pages, there is also a possibility that only the first page is sensed, or the like and the subsequent processes are omitted. In such a case, if the type of sheet is changed halfway of the stacked sheets, it is impossible to cope with it. Also in the case of sensing the sheet type during the conveyance, since it is necessary to immediately feedback the sensing result to the processing system of the printer main body, a load of the process increases.    5. There are many cases where the sheet type cannot be recognized until the sheet is fed depending on the construction on the printer side. This is because the optical sensor is often used as a media sensor which is installed and since it is necessary that a distance between the sheet and the media sensor lies within a range of a proper predetermined value, a state where the sheet existing halfway of the conveying path is pressed has to be set to the sensing position.    6. According to the type of sheet, a conveyance amount in motor drive control by the same torque differs. This is because a friction amount between the sheet and a roller differs in dependence on the type of sheet. If there is no means for previously grasping the sheet type, a sensor for determining a head position of the sheet is separately necessary. There is also a case where upon image creation of high quality, a slight difference of the conveyance amount affects in the image quality and becomes a problem.    7. In the case of the printer of the electrophotographic type, although the data is formed on the PC side, since it is necessary to finish the sheet specifying process in a very short time during the conveyance, a load of processes increases largely. To realize such an object, an arithmetic operation processing apparatus of a higher speed and higher performance has to be provided for the printer main body.